There is a good book written by noted expert Dr. Yang Jwing Ming called Yi Jin Ching/Shii Soei Ching. It discusses in depth the methods and translates many of the documents pertaining to these gongs. His work is different than most others who just publish the standing exersizes. The book actually gets into the conditioning, herbs and potions needed, training times and schedules. It is a very good read.
Kempoman